#2024motorcyclegroupbuild

Hosted by @gi_mechanicsscalemodeling and @jamiegsscalemodelgarage3823

0:09 Brake rotors are a pretty simple part, and the kit ones are well detailed...instructions say just detail paint and glue them on!

0:20 Ejector pin marks are a fact of life with any injection molded plastic part. Sometimes they are raised and only need to be sanded smooth but often they are recessed below the surface because the pins, which push finished "parts tree" out of the mold, make contact almost immediately after the plastic is injected into the mold. If the plastic is still a bit soft the pins leave an impression like the two visible in photo. Although the ones on the kit's brake rotors are on the back side and fairly well hidden it is easy to fill them in using disks punched from appropriate thickness of styrene sheet, in this example .020".

0:36 Glue in place with solvent cement (gap filling super glue can also be used)...

0:44...and sand smooth. Disk of a diameter that matches closely with ejector pin mark, and use of solvent cement, resulted in no gaps to fill.

0:58 A detail not molded into kit part is the fasteners attaching brake rotor to wheel. The real bike has 6...

1:13...but for model purposes I "cheated" slightly and installed 5. This is because there are 10 spokes so locating each bolt between a pair of spokes made it easy to space them equally.

1:24 Equal size bolt circle all around was done using short piece of 7/32" styrene tube as a spacer to make centre punch marks.

1:36 Holes were drilled .020" diameter...

1:42...and .030" diameter styrene rivet heads (Tichy Train group # 8019) glued in. These are another "cheat" as they are not hex head like the 1:1 but illusion of fasteners is convincing enough when assembled.

1:56 Excess length on back side is easy to trim off...

2:05...and sand smooth being careful to preserve locating pins. Back side of brake rotor is molded smooth, in contrast to the nicely done grooved texture on front (visible) side. An optional added detail is grooves on the back side. Not having a lathe in my tool collection, a lower-tech expedient was used...

2:32...sanding drum attachment for motor tool. Remove drum and washers...

2:43...and cut piece of 1/8" aluminum tube (brass can be used, aluminum is just easier to cut) approximately .050" long to use as a spacer due to the mounting pins on brake rotor.

2:54 Enlarge hole in brake rotor slightly with 3/32" diameter drill...

3:02...and assemble rotor onto sanding drum shaft. With motor tool at low speed, use razor saw to score grooves on inside surface of brake rotor.

3:18 These won't be as perfect as kit's molded-in grooves but on the back (less visible) side of brake rotor this subtle bit of added texture will be convincing enough.

#yamahamotorcycles

#scalemodelling